Electronic circuits

An electronic circuit is a network of components — such as resistors, capacitors, inductors, diodes, transistors and integrated circuits — connected by conducting paths so that electric current can flow along controlled routes. By arranging components in a particular configuration, a circuit can perform a useful function: amplifying a signal, generating an oscillation, regulating a voltage, switching a load on and off, or processing information. The behavior of the whole depends both on the individual parts and on how they are wired together.

Circuits are commonly grouped by what they do. Power circuits, including power supplies and battery chargers, deliver and regulate the energy other stages need. Amplifier and preamplifier circuits increase the strength of audio or radio signals, while oscillators and transmitters generate periodic waveforms or radio-frequency carriers. Control circuits handle tasks such as motor speed control, light dimming and switching, and measurement circuits drive meters and test instruments. Many practical designs combine several of these stages on one board.

Designing a circuit usually begins with a schematic diagram, which shows the components and their connections symbolically. The design is refined by calculation and often by simulation, then realized on a breadboard or printed circuit board for testing. Hobby and educational electronics rely heavily on shared circuit collections, where worked examples — from simple single-transistor stages to microcontroller projects — can be studied, built and adapted. Understanding a few recurring building blocks makes it possible to read and modify a wide range of designs.

Frequently asked questions

What is an electronic circuit?

An interconnection of components arranged so that current flows along controlled paths to perform a function such as amplifying, switching or regulating.

How are circuits usually classified?

By their purpose, for example power supplies, amplifiers, oscillators, control circuits and measurement circuits.

What is a schematic diagram?

A symbolic drawing that shows a circuit's components and the connections between them, used as the basis for building and analysis.